1. Field of the Invention
The present invention relates to engines, and more particularly, to internal combustion engines having five strokes.
2. Description of the Related Art
Many designs for internal combustion engines have been designed in the past. None of them, however, include a five-stroke internal combustion engine that provides for recycling some of the fuel-air mixture during a recycle stroke, and provides a greater power stroke to compression stroke ratio. Recycling of the fuel-air mixture during the recycle stroke improves fuel efficiency, power output, and decreases emissions. The five strokes are an intake stroke, a recycle stroke, a compression stroke, a power stroke, and the exhaust stroke. A condensed fuel-air separator for the fuel-air mixture and a recycle valve for that condensed fuel-air separator are part of the design.
Of the numerous designs for reciprocating internal combustion engines, most of them comprise four stroke/cycle designs. These type of designs lose efficiency during their power stroke when a piston reaches bottom dead center and the exhaust valve is in an open position, thereby interrupting the energy being produced by the expanding gas. This causes usable unburned expanding gas to combust outside of the combustion chamber into the exhaust system.
Applicant believes that the closest reference corresponds to U.S. Pat. No. 4,289,097 issued to Ward for Six-cycle engine. However, it differs from the present invention because Ward teaches an improved six-cycle engine that improves performance in fuel economy and in the power to size ratio. The six cycles are a first intake stroke, a compression and storing stroke, second intake stroke, a compression and combining stroke, the power stroke, and the exhaust stroke. The invention provides for using some of the fuel""s energy that ordinarily is lost in the engine""s cooling system, by absorbing heat after the first stroke and subsequently using it in the power stroke. A special configuration of a separate chamber for the compression of gases induced in the first intake stroke and a special configuration for the valve to that chamber are part of the design. Two induction cycles are included in the six cycles for each power stroke.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.
A five-stroke internal combustion engine that improves fuel efficiency, power output, and decreases emissions. The five strokes are an intake stroke, a recycle stroke, a compression stroke, a power stroke, and the exhaust stroke. The five-stroke internal combustion engine provides for recycling a portion of the fuel-air mixture during the recycle stroke and provides a greater power stroke to compression stroke ratio. A condensed fuel-air separator for the fuel-air mixture and a recycle valve for that condensed fuel-air separator are part of the design. The instant invention may be utilized for diesel, gasoline and natural gas type engines.
The first cycle is the intake stroke. A primary intake of fuel-air mixture (gasoline model) or air only (diesel model) enters into a cylinder as the piston travels in a downward direction a full longitudinal piston stroke. In the preferred embodiment, we assume that a full longitudinal piston stroke is 8 inches. The valve configuration for the intake stroke commands that the intake valve is open and the exhaust and recycle valves be closed.
The second cycle is the recycle stroke. The piston travels in an upward direction a predetermined distance, which in the preferred embodiment, is approximately one-half of the full longitudinal piston stroke. During this stroke, some of the fuel-air mixture is forced through the open recycle valve into the condensed fuel-air separator. The valve configuration for the recycle stroke commands that the recycle valve be open and the intake and exhaust valves be closed.
The third cycle is the compression stroke. The remaining fuel-air mixture in the cylinder is compressed as the piston continues to travel in the upward direction to the position of top dead center. The valve configuration for the compression stroke commands that the recycle, intake and exhaust valves be closed.
The fourth cycle is the power stroke. Upon ignition (injection diesel model) of a spark plug, expanding gas drives the piston in a downward direction a full longitudinal piston stroke. The valve configuration for the power stroke commands that the recycle, intake and exhaust valves be closed.
The fifth cycle is the exhaust stroke. As the piston travels in the upward direction, burned gas is expelled through the opened exhaust valve port. The valve configuration for the exhaust stroke commands that the exhaust valve be open and the intake and recycle valves be closed.
The fuel-air mixture collected in the aforementioned condensed fuel-air separator is cooled and separated, with the liquid fuel being returned to a fuel tank. Remaining fuel-air vapor is then returned to the combustion chamber via the intake manifold for another attempt at combustion in the repeating cycles.
More specifically, the instant invention comprises a housing structure and cylinder means. The cylinder means are encased in the housing structure. The instant invention further comprises crankcase means. The crankcase means are affixed to the housing structure. The instant invention further comprises crankshaft means. The crankshaft means are positioned in the crankcase means. The instant invention further comprises a valve system means. The valve system means consists of an air intake valve, a recycle valve, and an exhaust valve. The valve system means is affixed to the housing structure. The instant invention further comprises a condensed fuel-air separator. The condensed fuel-air separator is located at a predetermined distance in close proximity to the cylinder means and located within the housing structure. The condensed fuel-air separator communicates with the cylinder means through a first elongated connector. The recycle valve is located within the cylinder means and is so arranged so as to periodically at predetermined times for predetermined periods allow a fuel-air mixture to flow from the cylinder means through the first elongated member to the condensed fuel-air separator, when the recycle valve is in an open position.
The five strokes are: an air intake stroke; a recycle stroke; a compression stroke; a power stroke; and an exhaust stroke. During the recycle stroke, a predetermined amount of the fuel-air mixture received during the intake stroke, is compressed into the condensed fuel-air separator. The condensed fuel-air separator comprises a reservoir where the fuel-air mixture accumulates and liquid fuel is returned to a fuel tank. Remaining fuel-air vapor within the condensed fuel-air separator is returned to the cylinder means via a second elongated connector for another attempt at combustion in the cylinder means.
The reservoir comprises a fuel level sensor system that monitors liquid fuel level, and further comprises a float that opens a valve when the liquid fuel level reaches a predetermined level. This allows accumulated liquid fuel to return to the fuel tank.
The instant invention has a greater power stroke to compression stroke ratio. The condensed fuel-air separator improves fuel efficiency, power output, and decreases emissions of the engine.
The instant invention further comprises a piston and piston rod. The piston and piston rod are assembled in the cylinder means. The piston rod is assembled to the crankshaft in the crankcase means. The instant invention further comprises a fuel injection system. The fuel injection system has a fuel injection inlet into the cylinder means.
It is therefore one of the main objects of the present invention to provide a five-stroke internal combustion engine that provides for recycling some of the fuel-air mixture during the recycle stroke.
It is another object of this invention to provide a five-stroke internal combustion engine that provides a greater power stroke to compression stroke ratio.
It is another object of this invention to provide a five-stroke internal combustion engine that includes variable recycle valve timing to optimize engine efficiency, wherein retarding or advancing the recycle valve timing varies both the compression ration and the recycle ration.
It is another object of this invention to provide a five-stroke internal combustion engine that provides a condensed fuel-air separator as a means to recycle unburned fuel, wherein the condensed fuel-air separator can be air cooled or liquid cooled.
It is yet another object of this invention to provide such a device that is inexpensive to manufacture and maintain while retaining its effectiveness.
Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.